The proposed research will continue experiments on the pathogenesis and treatment of encephalitozoonosis. The project will emphasize studies designed to alter the course of, or prevent infection with Encephalitozoon cuniculi. There will be studies designed to determine the impact of latent encephalitozoonosis on the research value of laboratory rodents and will try to show the pathogenetic mechanisms used by the parasite to alter host immune responses. Mechanisms used by the host to control parasite spread or multiplication will be investigated and evidence will be sought that some chronic renal disease is due to encephalitozoonosis.